An emergency call with exact location information (e.g., from GPS—Global Positioning System) from a mobile telephone network uses a data channel (e.g., SMS or GPRS) and a speech channel in order to transmit the entirety of the emergency call information (e.g., location, cause of the accident, identity of the caller) to an emergency call center. The data supplied via the data channel must be synchronized with the speech channel in order that all the emergency information can be passed on together to the rescue center. The synchronization of incoming speech calls and the data (e.g., via SMS) takes place nowadays within the context of location-related services via the call number of the customer (MSISDN—Mobile Subscriber Integrated Services Digital Network Number) with support from ACD (Automatic Call Distribution) systems and CTI (Computer Telephony Integration) functions. The MSISDN (call number) is contained within the signaling data or the data themselves. For the speech connection, the MSISDN is usually transmitted to the telecommunication system at the service center (e.g., call center), when the customer has switched on the CLIP (Calling Line Identification Presentation) or has accessed the speech connection of the service center via the CLIR Overwrite (Calling Line Identification Restriction) feature (the suppressed CLI is nevertheless displayed). The synchronization then takes place in such a manner that this MSISDN is made known to the system for speech processing (e.g., the client workstation of a call center agent). The data belonging to this speech call with this MSISDN is meanwhile present in a database with the identification feature MSISDN from the data transmission and can therefore be assigned to the speech channel.